Henry V was probably helped out by his half-grandnieces: Princesses Elizabeth and Joanna Tudor, who, as it is well known, eloped with William S. Preston and Theodore Logan, with the assistance of Socrates and Napoleon Bonaparte, in a somewhat worse for wear late twentieth century North American touchtone telephone booth.

During the ample period when the two girls worked as backup musicians to their paramours and later husbands, spanning their arrival at San Dimas in 1989 to the group's subsequent expedition to colonize Mars, they would have had access to the booth and could easily have assisted Henry in a few acts of trans-temporal fratricide.

OR it could have been a very slow acting poison.

Seriously though, the tract does not get much better after it gets to Massachusetts. It puts Benjamin Franklin in as US Postmaster General a good 50 years too early, claims that a tavern in Ipswich Massachusetts was a frequent haunt of John Hancock and Samuel Adams, which seems a bit unlikely given that Ipswich is a good 30 miles from Boston, twice the distance to Lexington and Concord.

I found what appears to be a somewhat less idiotic family history here (http://www.angelfire.com/mi4/polcrt/Perkins.html). It would appear "Humphrey Plantagenet Earl of Gloucester", is a conflation of Thomas Despenser And Thomas of Woodstock And poor old Humphrey. Hard to say how Edward Despenser and Edward III Plantagenet got muddled up in the author's mind though. I get the impression that this was written as a high school assignment, it certainly has a level of fact-checking, hearsay acceptance and one draft/one version thinking that would make Herodotus take a step back and shake his head.

I poked around the internet to see what portions of the American Perkins "folklore" that can't be authenticated against the more reliable genealogy might have any level of accuracy. In no particular order:

Henry Coit Perkins actually is the founder of Harvard's Astronomy Professorship, although the chair apparently now belongs to the applied mathematics department. It is currently held by one Vahid Tarokh, who appears to be of Iranian-Canadian extraction. The thought of how Henry would react to this amuses me. His dates are generally given as 1804-1873, so his graduation date of 1954 must be a typo. Only Yale graduates skull and bones men.

Jabez Huntington was indeed a Major General in the Connecticut Militia. This is not the same thing as a Major General in the Continental Army. It'd be more akin to being a 4-star Admiral of the US Coast Guard. (The Commandant of the Coast Guard, the Surgeon General, and the head of the NOAA are not part of the Joint Chiefs of Staff and do not get invited to the cooler Pentagon parties.)

"General" Joseph Perkins didn't exist, although there was a Colonel Joseph G. Perkins, and he does not appear to have been killed.

Lucretia Shaw Woodbridge Perkins seems to have lived in a completely different period, had nothing to do with the union movement, and seems to be confused with Frances Perkins, the US Secretary of Labor.

Elias Perkins Sr. was one-term US Congressman from Connecticut, but I find it laughably unlikely that he would have been a "confidant of General George Washington". He was barely a boy in Washington's military period and while he was a Federalist he did not begin his political career until a year before Washington's retirement.

Elias Perkins Jr. does seem to be buried in Hawaii, and is mentioned in a NYT article I'm too cheap to get a subscription to too read.

George Wallbridge Perkins not only existed but is much more interesting than his blurb would indicate. He was one of the organizers of Theodore Roosevelt's "Progressive Party" one in a long line of attempted US 3rd Parties. His inclusion actually caused a fracture in the party, since he was in favor of corporate monopolies and Roosevelt's progressive constituents were, to put it mildly, not.

George Wallbridge Perkins Jr. was a typical Republican Cold Warrior, close personal friend of Tito, and another in my country's long line of hack patronage-selected diplomats.

The Shadow Top/Able One family appears to have existed in Washington, although that's a bit far afield from the stomping grounds of all these other Perkinses.

One more zinger, the thought of a man born in 1390 fathering a child in 1390 reminds of the American cinema masterpiece:

"Don't Be a Menace to South Central While Drinking Your Juice in the Hood"

Which is one of the few entertaining Wayans Brothers films. It is not a movie for the easily offended, but the inciting incident is that the main character Ashtray's mother sends him to live in the Los Angeles ghettos with his father, who is clearly younger than he is.

The entire thing is a fairly relentless parody of African-American "ghetto" films, so it would probably make very little sense to a British viewer.

On the other hand, it could be argued that gangland urban America is the closest thing the English speaking world has got to a feudal society.